JDBC操作數據步驟
1.加載驅動(驅動數據庫:有三種方式,常用反射加載)
2.獲取連接對象(建立從java到數據庫的連接通道)
3.獲取處理命令的對象(通過連接對象想數據發送並執行sql語句)
4.執行sql操作
5.處理結果
6.資源關閉
實際操縱如下:
insert添加操作:
//1.加載驅動
Class.forName("com.mysql.jdbc.Driver");
//2.獲取連接對象
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "123456");
//3.獲取處理命令的對象
String sql = "insert into dept(dno,dname,tel) values(1,'市場部','111')";
PreparedStatement ps = conn.prepareStatement(sql);
//4.執行sql操作
int i = ps.executeUpdate();
//5.處理結果
if(i){
System.out.println("執行成功,影響數據行數:"+i);
}
//6.資源關閉
stat.close();
conn.close();
delete刪除操作:
//1.加載驅動
Class.forName("com.mysql.jdbc.Driver");
//2.獲取連接對象
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "123456");
//3.獲取處理命令的對象
String sql = "delete from dept where dno=1";
PreparedStatement ps = conn.prepareStatement(sql);
//4.執行sql操作
int i = ps.executeUpdate();
//5.處理結果
if(i>0){
System.out.println("執行成功,影響數據行數:"+i);
}
//6.資源關閉
stat.close();
conn.close();
update修改操作:
//1.加載驅動
Class.forName("com.mysql.jdbc.Driver");
//2.獲取連接對象
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "123456");
//3.獲取處理命令的對象
String sql = "update dept set tel='123456' where dno=2";
PreparedStatement ps = conn.prepareStatement(sql);
//4.執行sql操作
int i = ps.executeUpdate();
//5.處理結果
if(i>0){
System.out.println("執行成功,影響數據行數:"+i);
}
//6.資源關閉
stat.close();
conn.close();
select查詢操作:
//1.加載驅動
Class.forName("com.mysql.jdbc.Driver");
//2.獲取連接對象
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "123456");
System.out.println(conn);
//3.獲取處理命令的對象
String sql = "select dname as name,dno as no,tel as phone from dept";
PreparedStatement ps = conn.prepareStatement(sql);
//4.執行sql操作
ResultSet rs = ps.executeQuery();
//5.處理結果
while(rs.next()){
//已經獲取一行數據
String name = rs.getString("name");
int sno = rs.getInt("sno");
String tel = rs.getString("phone");
System.out.println(sno+"/"+name+"/"+tel);
}
//6.資源關閉
stat.close();
conn.close();